1. Field of the Invention
The present invention relates to a water-cooled multipart hood for metallurgical vessels, particularly pouring ladles, with cooling tubes arranged welded tube against tube and/or with gaps between the tubes, with an opening arranged in the cover of the hood for inserting a refractory core piece for guiding electrodes therethrough, and with openings for discharging flue gases.
2. Description of the Related Art
In the operation of ladle or pan furnaces for the metallurgical after treatment of steel melts from converters, arc furnaces or the like, the hot and dust-containing waste gases are prevented from being discharged over the ladle rim into the surrounding building by exhausting the waste gases through a pipe connection provided at the ladle hood. In addition to exhausting the waste gases through the openings at the ladle hood, additional exhaust locations are provided at the ladle hood which overlaps the ladle rim of the steel pouring ladle, or the ladle hood is placed on the ladle rim or an additional support device is provided.
DE 31 47 337 C2 discloses a water-cooled hood for metallurgical vessels, particularly-pouring ladles, with collar and cover part, wherein the hood is composed of cooling tubes which are arranged either tightly together or with small gaps therebetween, wherein the cooling tubes are combined to form a meandering cooling water circulation by means of caps placed on the cooling tubes. The collar is essentially composed of vertically extending cooling tubes. The cover part is composed of cooling tubes extending in the circumferential direction, on the one hand, and a self-supporting core piece or heart piece, on the other hand, wherein the core piece has three round electrode passages which are offset relative to each other by 120.degree., wherein the electrode passages are surrounded by cooling rings composed of a plurality of cooling tubes extending above one another in the circumferential direction of the electrode passages, wherein the cooling rings come together in the center of the cover part and upper support flanges are welded to the outer sides of the cooling rings, wherein the upper support flanges extend with gussets between the electrode passages.
DE 34 27 086 C1 discloses a metallurgical vessel with a heat shield arranged so as to leave a peripheral air gap thereabove, wherein the heat shield has at least one opening through which a probe, lance or electrode is guided from the outside into the interior of the vessel. The metallurgical vessel further has a downwardly open exhaust hood which is placed around the heat shield and surrounds the vessel so as to protrude beyond the peripheral air gap. The air space formed between the heat shield and the exhaust hood is connected to an exhaust device. In order to produce a metallurgical vessel of the above-described type which ensures an exhaust of the process gases and dusts and simultaneously ensures an effective shielding of the ambient air from the metal melt, a separating wall was arranged within the exhaust hood so as to completely outwardly protrude beyond the peripheral air gap, wherein the separating wall forms together with the wall of the exhaust hood an intake nozzle which surrounds the vessel.
DE 42 24 845 A1 discloses a device for sealing a circumferential gap between a steel pouring ladle and the water-cooled ladle hood of a ladle furnace heated by electrodes. This configuration is intended to prevent the large quantity of flue gases, which are formed as a result of a chemical reaction when additives and alloying agents are suddenly added, from unimpededly being discharged into the surroundings. A gas-conducting pipe is mounted at the lower part of the ladle hood. By providing this pipe with a plurality of bores arranged within an angle range of 45.degree. toward the top and toward the bottom, gas is discharged from this pipe with excess pressure and forms a gas veil for sealing the gap between the steel pouring ladle and the water-cooled ladle hood.
The ladle hoods described above have the disadvantage that the sealing effect at the outer cover area for the passage of lances or electrodes is insufficient and the exhaust of the hot flue gases in the upper part of the ladle hood is not satisfactory.